The present invention relates generally to an optical fiber buildout assembly for use in coupling a first optical fiber cable to a second optical fiber cable. More particularly, the invention relates to an improved sleeve holder for being received within a buildout cap of the optical fiber buildout assembly for holding an alignment sleeve therein.
The use and construction of optical fiber cables, and optical fiber buildouts used for coupling optical fiber cables together is well known. Optical fiber cables are provided with optical fiber connectors at their ends, the optical fiber connectors being one of several known types of connectors namely being either an SC, an ST(copyright), an FC, and/or an LC type of optical fiber connector. The SC, ST(copyright) and FC connectors are provided with 2.5 mm diameter ferrules, whereas the LC type of optical fiber connectors provide 1.25 mm diameter ferrule.
The earliest type of optical fiber couplings did not use buildouts as such, but rather they were formed as elongate adapters or connectors having a elongate bore defined along a longitudinal axis and within which an alignment sleeve would be positioned. The alignment sleeve was sized and shaped to receive, at each of its respective ends, a separate ferrule from one each of the two optical fiber connectors to be coupled. In these early optical fiber couplers, the alignment sleeve was typically passed over the end of one of the ferrules first, the ferrule bearing the sleeve then being passed into the coupler, whereupon the ferrule of the other optical fiber connector was passed into the coupler and the sleeve for completing the coupling. These alignment sleeves typically floated freely within the coupler, being held in position only by the retainer cap.
As the development of optical fiber buildouts occurred, in which a separate base and cap were used to assemble the optical fiber cable coupling, alignment sleeve holders were developed in which the alignment sleeve would be positioned such that the alignment sleeve need not first be passed into the cap and retained by a retainer cap. The problem with these types of sleeve holders, however, was that they required the use of a separate retainer cap to hold the alignment sleeve within the body of the sleeve holder, or housing. The retainer cap could become lost, or was difficult to handle in the field, which made it difficult to ensure that the retainer cap was properly secured on the sleeve holder which could result in the alignment sleeve falling out of the buildout during the buildout assembly process.
As a result, therefore, sleeve holders were developed which dispensed with the need for these retainer caps, an example of which is the sleeve holder disclosed in U.S. Pat. No. 5,838,855 to Stephenson entitled, xe2x80x9cSleeve Housing for Optical Coupling Buildoutxe2x80x9d assigned to Lucent Technologies, Inc, the assignee of this invention. The sleeve housing of the ""855 patent to Stephenson had a cylindrical body portion, one end of which was constructed to allow the alignment sleeve to be passed therethrough and retained within the alignment sleeve holder. As a result, the sleeve housing was able to retain the alignment sleeve without the need for a separate retainer piece.
Although the sleeve housing of the ""855 patent to Stephenson was a significant advance in the art, the need remains, however, for a simple alignment sleeve housing or holder which can be quickly and easily used in the field, and is sized and shaped to be snap-fit into a buildout assembly for making it easier still to assemble optical fiber buildouts. Moreover, there is a need for such an improved type of sleeve holder which can be used for the larger 2.5 mm diameter ferrules, which can also be used for holding alignment sleeves for 1.25 mm diameter ferrules such that the respective sleeve holders can be quickly and easily snapped into the buildout cap of an optical fiber buildout assembly, and for a step sleeve for a 1.25 mm to 2.5 mm that can be snap-fit into a buildout assembly.
The present invention provides an improved sleeve holder for an optical fiber buildout which overcomes some of the deficiencies of the known art. The sleeve holder of this invention provides a simple, efficient, and highly flexible device for quickly and easily assembling an optical fiber buildout in the field, and for reliably holding an alignment sleeve therein, either with or without an attenuator element within the alignment sleeve. The relative simplicity and ease of use of the improved sleeve holder of this invention provides a greater degree of reliability and ease of use, when contrasted to the known devices, when used in the assembly of an optical fiber buildout or buildout assembly.
This invention attains this high degree of flexibility and simplicity by providing an improved sleeve holder for being received within the cap of an optical fiber buildout assembly. The sleeve holder comprises an elongate tubular body formed about a longitudinal axis, the body having a first end and a spaced second end. A first slot is defined in the first end of the body, and extends longitudinally from the first end of the body toward the second end thereof. A first annular shoulder is defined within the first end of the body about the longitudinal axis, and a second annular shoulder is defined within the second end of the body about said axis, the second shoulder being spaced from the first shoulder along the axis. An annular mounting flange is formed on the exterior surface of the body intermediate the ends thereof, the flange extending outwardly of the axis and away from the body, which mounting flange is sized and shaped to be universally snap-fit into a buildout cap.
The sleeve holder may include a second slot defined in the first end of the body and spaced radially from the first slot, these two slots together defining a pair of legs within the body, the legs being constructed and arranged to be resiliently urged outwardly of the axis of the tubular body and away from one another for allowing the alignment sleeve to be passed therethrough and into the sleeve holder, whereupon the alignment sleeve will be captured therein by and between the first and second shoulders. Accordingly, the first and second shoulders are spaced a distance sufficient to capture the alignment sleeve within the tubular body of the sleeve holder.
The sleeve holder may further comprise an elongate third slot defined therein, the third slot extending substantially toward the second end of the body from one of the first and second slots, respectively, as desired. This third slot will provide access to the elongate attenuator slot formed in the alignment sleeve, and will permit the use of an attenuator with the sleeve holder and the alignment sleeve. The mounting flange of the tubular body will have at least one snap-fit tab, and preferably two radially spaced snap-fit tabs provided as a part thereof, the snap-fit tabs being sized and shaped to snap-fit within a buildout cap.
The alignment sleeve of the present invention may be used, therefore, with any one of the several differing types of buildout bases or caps, including SC, ST(copyright), FC, and LC bases and caps, respectively. In a first embodiment the alignment sleeve holder can be used for the larger 2.5 mm ferrule optical fiber connectors comprising the ST(copyright), SC and FC optical fiber connectors; and in a second embodiment, by sizing the diameter of the tubular body smaller, the sleeve holder of this invention may be used to couple two LC optical fiber connectors together.
It is, therefore, an object of the present invention to provide an improved sleeve holder for use in an optical fiber buildout.
It is another object of the present invention to provide an improved sleeve holder which is simple in design and construction, is rugged and durable in use, and is easy to use when assembling an optical fiber buildout assembly.
It is to these objects, as well as the other objects, features, and advantages of the present invention, which will become apparent upon reading the specification, when taken in conjunction with the accompanying drawings, to which the invention is directed.